Which of the following metals is most reactive? a. Mg b. Rb c. Cs d. Li

Which statements are true of a heterozygous mixture ?

Maksim231197 [3]

Answer:

b

Explanation:

2 +4

3 0

3 years ago

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What structure do all of these elements have in common?

Dmitrij [34]

The answer is c because of going left to right

7 0

3 years ago

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The rate constant k for a certain reaction is measured at two different temperatures temperature 376.0 °c 4.8 x 108 280.0 °C 2.3

9966 [12]

Answer:

The activation energy for this reaction = 23 kJ/mol.

Explanation:

Using the expression,

$\ln \dfrac{k_{1}}{k_{2}} =-\dfrac{E_{a}}{R} \left (\dfrac{1}{T_1}-\dfrac{1}{T_2} \right )$

Where,

$k_1\ is\ the\ rate\ constant\ at\ T_1$

$k_2\ is\ the\ rate\ constant\ at\ T_2$

$E_a$ is the activation energy

R is Gas constant having value = 8.314×10⁻³ kJ / K mol

$k_2=2.3\times 10^8$

$T_2=280\ ^0C$

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (280 + 273.15) K = 553.15 K

$T_2=553.15\ K$

$k_1=4.8\times 10^8$

$T_1=376\ ^0C$

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (376 + 273.15) K = 649.15 K

$T_1=649.15\ K$

So,

$\left(\ln \left(\:\frac{4.8\times \:\:\:10^8}{2.3\times \:\:\:10^8}\right)\right)\:=-\frac{E_a}{8.314\times \:10^{-3}\ kJ/mol.K}\times \:\left(\frac{1}{649.15\ K}-\frac{1}{553.15\ K}\right)$

$E_a=-\frac{10^{-3}\times \:8.314\ln \left(\frac{10^8\times \:4.8}{10^8\times \:2.3}\right)}{-\frac{96}{359077.3225}}\ kJ/mol$

$E_a=-\frac{\frac{8.314\ln \left(\frac{4.8}{2.3}\right)}{1000}}{-\frac{96}{359077.3225}}\ kJ/mol$

$E_a=22.87\ kJ/mol$

The activation energy for this reaction = 23 kJ/mol.

6 0

2 years ago

Calculate the molar mass of a gas

spin [16.1K]

Answer:

MOLAR MASS = 32 g/mol

Explanation:

Condition of standard temperature and pressure(STP) are as follow:

Temperature = 273 K

Pressure = 1 atm (or 100000 Pa)

Here atm is atmosphere and Pa is Pascal

STP conditions arte used for measuring gas density and volume using Ideal Gas Law.Here 1 mole of ideal gas occupies 22.4 L of volume.

According toi Ideal Gas Equation :

PV = nRT

where P = pressure, n= number of moles, V = volume ,R= Ideal Gas Constant and T= temperature

$n=\frac{PV}{RT}$

From question:

V=280 ml = 0.28 L

P = 1 atm

R=0.08205 L atm/K mol

T=273 K

Putting values in above formula :

$n=\frac{1\times .280}{0.08205\times 273}$

n = 0.0125 moles

Now $n=\frac{given\ mass}{Molar\ mass}$

$Molar\ mass=\frac{given\ mass}{n}$

given mass = 0.4 g (given)

$Molar\ mass=\frac{0.4}{0.0125}$

On solving we get:

Molar mass = 32 g/mol

4 0

3 years ago

What is the gram molecular weight (GMW) of CuCl2?

Nuetrik [128]

The molar mass of CuCl2 is 134.452 g/mol. Each element's molar mass can be found in its designated box on the periodic table.

8 0

2 years ago